Removing the MAF screen

[Fastlanev6]

Does this little mod bring any performance gains at all? I do know that in the 3100 the HP rating went down by 5 when they added the MAF sensor to it. Input? Thanks!

[eric99gt]

don't do it....ppl have had nothing but problems with this mod.

[Fastlanev6]

10-4

[99GrandAMSE]

Originally posted by eric99gt
don't do it....ppl have had nothing but problems with this mod.

... actually, I have never heard anyone having problems directly associated with the removal unless the "hot wires" were damaged ... now, whether or not removing the screen really made a difference is a another story ... I removed the screen from mine, plus, I removed the baffle running across the middle and while I certainly haven't experienced any problems due to this, I don't believe it helped a whole bunch either ... yes, I it assisted a LITTLE on the top end but I don't believe any money used on the removal would be well spent (mine was basically free) ... just my two cents anyway :)

[Fastlanev6]

the million dollar question....is it worth the effort?

[99GrandAMSE]

... if you do it yourself and don't pay anything for it, in my opinion, SURE ... but if you have to pay for it, I would spend the $$$ on something 'better'

[eric99gt]

I've heard of plenty of ppl have problems running lean over on GAGT. I myself was one of them. Since have gone back to stock and it's a charm.

[99GrandAMSE]

Originally posted by eric99gt
I've heard of plenty of ppl have problems running lean over on GAGT. I myself was one of them. Since have gone back to stock and it's a charm.

... I didn't say it NEVER happened but I haven't heard of too many (actually, I still can't remember hearing of anyone with problems that were directly related to removing the screen; although, this topic has always be popular ... got to remember that there are MANY members in common between the two sites) ... regardless, I bet if the truth were known, most of the problems would be associated with a malfunctioning "hot wire" and not due to the screen being moved ... anyway, no matter, I can only go by my experience and from what I have read all these years :)

[eric99gt]

I've been reading just as long lol. In my opinion the benefit does not outweigh the possible negatives.

[doobiess]

its like those mod chips you see on ebay .. all they do is add the resistor to a sensor to actually make the car run more rich.. which in turn give you the power you have when your car is still warming up but all the time.. Well the problem with doing that is having too much fuel to air mixture will eventually foul your plugs dirty the internal of your engine.. should cause more heat, making it more likely to overheat and so on. So bassically what im saying is there is a reason why GM puts these sensors in thier engines... since its not like they havent designed an engine before....

[99GrandAMSE]

Originally posted by eric99gt
... In my opinion the benefit does not outweigh the possible negatives.

Like I said, in my opinion, the negative possibilities are minimal unless you damage the "hot wire" :) ... for interest sake, how long have you been reading?

[mikem220153]

I had considered doing the mod but had 2nd thoughts. My reservations to doing it were the possibility of something coming down the air tube and either getting sucked into the engine or having it hit the filiments on the MAF and causing debris from that going down the motor.

[intake68]

If you remove the sreens from either end it distorts the readings that the MAF is sending to the ECM. The more airflow at WOT, the more potential for readings that are incorrect. There is no way a 3400 engine will max out the MAF any time soon. I ran a stock MAF on an 89 Trans Am GTA and it was a proven 12 second car at the track. GM has very accurately calibrated the MAF. Even the oil from K&N filters can cause false lean conditions. I had a 98 T/A just recently that had to have a lot of fuel added in the tune to get the desired AFR at part throttle. Turns out once we cleaned the MAF, the AFR showed closer to 10:1 on a IM WBO2. The cause was the oil used on K&N filters or equivilant. The oil is drawn off the filter and lodges on the hotwire on the MAf thus taking more current to keep the wire at a certian temp, thus telling the car its moving more air than it actually is. The ECM then throws in more fuel. I have programmed many BIN files and flashfiles for GM ECM's. Take it from me, don't play with your MAF unless you have the urge to spend a few hundred bucks fixing a mistake. The best case scenario is that your mileage drops slightly from the incorrect readings even tho your car *seems* to run the same. At the same time you will be convinced that the old SOTP dyno says there is more power now. The worst case scenario is you buy a new MAF. ;)

[99GrandAMSE]

:lol: ... from now on, I am gonna keep my mouth shut as it is obvious I don't know what I am talking about :roll: ... thanks to everyone for setting me straight and will rush right out tomorrow and put my stock MAF back on :wink4: [/end sarcasm]

[intake68]

Hey Kelly its nice to see someone who is always open to further learning. Maybe you can explain why it does not affect the MAF readings???? And no I don't want to hear your opinion, I want to hear some evidence that supports your advice. What is your AFR at idle/part throttle??? What are your BLM's or INT throughout the fuel cells?? I shudder to think of all the great free advice offered on the net sometimes. I do not know everything either but I can back up my advice given with actual hard numbers not second hand inforamtion. I also don't mind being wrong I just don't want to see advice given out that could potentially harm driveability and cost money all for NO gain. Unless you can program your PCM and understand how to calculate MAF scalars and what these tables change when modified then I still say don't do it.

[99GrandAMSE]

... sarcasm aside, I am ALWAYS open to learn new things but people have to remember all the number crunching in the world cannot be subsitutued for actual results (have you never calculated something and determined it wouldn't work but tried it anyway only to find out it really did work? :D) ... in regards to whether or not I put my car on a dyno, no as they a few and far between in my neck of woods so I'll have to rely on my experience and the fact it is much easier to 'feel' even a small increase in power to a low horsepower car than it is on a high horsepower car ... I can asure you though, it did make a difference ... did it make 10 HP, no ... did it make 5 HP, again no ... will it work on absolutely every car, of course not, but it honestly made a difference to mine on how 'freely' it accelerates on the top end ... same idea goes for the factory RAM-AIR system being everyone says they "do not work" when in fact they do work but it is just a matter of degrees as to how much power you get compared to how much more you'll get with something else (more commonly a CAI is being installed as a replacement) ... also, in case you're thinking I made a bunch of changes at once and could not tell what was actually causing the change, well I made individual changes so I know for certain the increase on which I speak was due to this specific modification ... you also mentioned my AFPR; however this was done for necessity being I only had 42 PSI of fuel at WOT (if I recall correctly) when it should have been around 50 PSI (again, if I recall correctly, as it has been a while since I looked at the numbers) ... this addition made a big differece too, if you're interested :)

Another frequent topic of discussion and whether or not the modification is worth it, is a ported TB ... in my case, I also have this done (in case you didn't know) ... now this also made a difference but it was minimal and probably wouldn't be worth spending a great deal of money on ... in my case, I was able to get these modifications fairly cheaply and I got to keep all my original parts ... I guess it all comes down to how much someone is willing or wants to spend on a modification ... going out and spending a couple hundred dollars on a ported MAF would not be worth it but if it was cheap enough, as in my case, I do support the change ... same theory of economics goes for the TB being it isn't worth spending too much on ... I will refrain from commenting too much on the AFPR as my appreciation of it has more to do with the fact I *needed* it rather than *wanting* it :)

Finally, I noticed my reply above might be a little too sarcastic or agumenative and as such, I offer my apology :) ... I was having a "bad day" and I should not have taken it out on you ... I do sometimes get out of hand despite the fact I own half the place ... nice to chat with you as you seem to be very intelligent and knowledgable ... enjoy the board!

[intake68]

Hi Kelly I wasn't trying to raise a stink so thanks for realizing that:) In my first post I used the abbreviation SOTP dyno. That simply is the "seat of your pants" dyno or "butt" dyno. The butt dyno I have found out over the years is a very inaccurate instrument:P To be honest it is imposible to feel a 5hp increase even on a 170HP car with any accuracy. I have spent countless hours on a dyno with various cars from imports through domestic and I have had the pleasure of seeing first hand how many of these "mods" relate to actual HP numbers.

Also when I abbreviated AFR it was for air/fuel ratio not adjustable fuel pressure regulator or AFPR. AFR on a 3.4l at idle/part throttle is set at 14.7:1 or stoich. Your car's computer relies on info from sensors to know how much fuel to add in relation to how much air is being drawn. The ECM relies heavily on MAF readings to interpolate airflow. If that initial reading is changed(IE descreen the MAF and now more airflow passes through than what the sensor knows) then it takes the ECM forever to compensate for this problem if it can at all. It will be trying to toggle the AFR and at the same time bring integrators down to level out the BLM's because it is getting an airflow reading from the MAF but the 02 is telling it that its lean. When you run your car at WOT it does not look to the 02 sensor for a final reading on AFR but rather uses the MAF scalars,TPS readings, ect to calculate how much fuel to dump in. If it is using a value from a MAF table in scalar#6 at 200gms/sec even tho there is 220gms/sec passing through it will never know it. Thats why people use WB02's for tuning at WOT. What often happens is that GM is "safe" on its original programming making its vehicles run more on the rich side than the lean side. When removing a MAF screen and allowing more air to pass than whats being read and running the car at WOT it will run the car LEANER. REmember the computer will not add more fuel at WOT to compensate for a lean condition. Leaner is faster but the ECM can not monitor AFR at WOT remember. Leaner can also kill a motor very prematurely. The computer can adjust AFR at part throttle with the 02 sensor but not when running with your foot to the floor. Kep in mind this is only one possibility. Unless you datalog your car and have a WB02 its impossible to say exactly whats going on in each situation. The overall condition of the motor and state of tune will all play large parts in how the car reacts.

Think of an engine like a pump. More air in and more air out is more power. Removing restrictions always will increase performance. Opening up intake ducting helps, porting a throttle body as you have done can improve part throttle/tip in, less restrictive exhaust is up there as well. But changing a sensor so that it scews readings is not a good one.

What CFM does a 3/4l MAF flow anyhow??? I know that the MAF on my GTA flowed 540cfm . 540cfm was enough air to support 400hp at the crank. And my MAF was quite a bit smaller than the MAF on this Grand Am. My GTA dynoed at 462ft/lbs RWTQ and 312RWHP.

[99GrandAMSE]

... it is quite obvious you are one who likes 'numbers' and being a CET, I can appreciate that but you have to realize I am more "in tune" (pardon the pun) with older cars so I don't really care about all the technical/electrical information you provided or do I take note very often since my Grand Am is mainly a toy with a little bit of go and a little bit of show :lol: ... to be blunt, I am old school and much prefer to make horsepopwer with big block engines with carburators and rear wheel drives :) ... I know how computer controlled engines work (probably not to the obvious extent you do) but rest assured I am no novice when it comes to our cars or the "feeling" of power increases regardless of them being small or large ... I disagree with your statement about not being able to feel 5 HP though, but we could argue about this point all night :lol: ... I may not have spent hours in or around a dyno, but I have spent enough time in various dragsters and whatnot over the years to know my SOTP dyno works well :wink4:

Anyway, I am a little bit embarrassed that I thought you were referring to the AFPR (I read your post three times as each time I saw a "P" in there :lol: :D) and at the time, I couldn't understand why you wanted to talk about fuel pressure but I felt, why not :) ... I guess we will just have a agree to disagree on this one bud :)

Finally, for interest sake, your GTA would seem to have similar power to my Camaro but again, I don't have a local dyno to confirm but CALCULATED, my car should have similar numbers ... put it this way, I know it will do a low 13 second run spinning all of 1st and 2nd so with a set of 3.73s and a posi, mid 12s wouldn't be a problem ... I also have a TA but it is mainly stock with a 400BB :)

Once again ... nice talking :)

[intake68]

I just wanted others to learn a little bit and base their decisions off fact. I was trying to show you that it was not based on what my opinion was. I too am "old school" or just old for that matter and have had many impressive vehicles that were carbed but that has no place in this thread :) If anyone stumbles across this thread and has any questions they can shoot me a PM as I don't want to stink it up by rambling on.....bottom line is don't play with that MAF kids:cool:

[99GrandAMSE]

Originally posted by intake68
... bottom line is don't play with that MAF kids:cool:

Like I said, we'll agree to disagree! :)

[intake68]

:P If I actually crammed in fecal matter into my gas tank and honestly believed it made my car faster because it raised octane do you think it meant that it actually was true.....no it means I have shvt in my tank. Opinions are fine but you can't base good advice on what you "think". Thats only your opinion. If someone actually wants to know how it affects the cars operation then they need to know what truely happens when the screens are removed. I personally don't care too much about it all I just wanted some actual info to be posted about it rather than opinions, thats all:lol:

[sunrunner_pei]

Originally posted by intake68
:P If I actually crammed in fecal matter into my gas tank and honestly believed it made my car faster because it raised octane do you think it meant that it actually was true.....no it means I have shvt in my tank. Opinions are fine but you can't base good advice on what you "think". Thats only your opinion. If someone actually wants to know how it affects the cars operation then they need to know what truely happens when the screens are removed. I personally don't care too much about it all I just wanted some actual info to be posted about it rather than opinions, thats all:lol:

:shake: Man, you just don't give up, do you? You posted your 'factual' information, that should be enough.

[Colin]

I've said it before and i'll say it again , the screen is there to straighten out the airflow so the meter can more accurately measure the airflow . Leave it alone ......

[99GrandAMSE]

... this could get old fast :lol:

Well, my "actual info" is the fact it worked on my car (and 3 other cars I can think of off the top of my head) so it is not opinion ... like I said all along man, it doesn't make 10 HP difference but it does make some and I believe (yes, this part is opinion) most problems associated with the removal come moreso from the owner damaging the hot wires and not because of any faulty readings ... I tried the car with ONLY the screen removed and it made a small change, then, I changed the MAF completely with a ported one (the baffle plate was also removed) and it made even more difference so I don't know how many more facts you want :shrug: ... as my last post in this regard, I say removing ONLY the screen is probably not worth spending any cash but if you go and port the MAF as well, then yes, I believe it is as shown in the results from my car ... could I calculate or PROVE exactly why it worked for me, sure but why would I do that when I can tell interested parties of my experience that is does and if they don't believe me that is their problem :lol: ... I'll leave you with this, I am not suggesting that everyone go out and do this but if they do, it has been my EXPERIENCE it does make a difference; although, probably not worth the money if you had to pay for it

Finally, in regards to octane levels, I am a believer that higher octane ratings make our engines work better too ;)

[99GrandAMSE]

Originally posted by Colin
I've said it before and i'll say it again , the screen is there to straighten out the airflow so the meter can more accurately measure the airflow . Leave it alone ......

... that is probably the SAFE thing to do if you're not sure Colin ... I have no problem admitting there may be some people who have had problems in doing what we are discussing but all I can go by is my experience ... it all comes down to common sense and what makes the individual the most happy :)

[Fastlanev6]

I think I should stop asking questions...it starts disputations :D

[Oldcat]

As you search around the boards you will find some who have had good results with this and some who have not. Same on the 3800's--some like it some don't. It seems to help if the MAF is put on right after the TB and has straight, smooth pipe after it. Check around on the Zzperformance info pages for some good info on this mod.

[eric99gt]

Originally posted by 99grandamse
Like I said, in my opinion, the negative possibilities are minimal unless you damage the "hot wire" :) ... for interest sake, how long have you been reading?

lol....way back when jason still ran gmpower. I've been around since the beginning of ga forums.

[Themeneea]

i would keep it just becuase its a last barrier for large objects. i once had my cone open up, and i found some crap stuck on the screen

[Old Guy]

Wheew!!!! Took me a while to sift through the B.S. but I finally made it to the bottom of the thread.

Most of you know I spent quite a bit of time at Pro M in order to get a recalibration on a new MAF for the 3400. My car was used as the model for the calibration and was dynoed wiith the stock MAF on the CAI and also with the new recalibrated MAF. I can't find the dyno sheets any more but the end results were something like this.

With the stock MAF on a CAI I had several flat spots on the power curve and slight detonation because the stock MAF is actually calibrated for the stock air box, which is also a reason that the screen is in it. As Colin said, it's there to straighten air flow for more consistant readings. The stock air box and that crap accordian rubber connector between the box and MAF certainly has to mess with the air flow.

The recalibrated MAF did not have a screen in it and the bore matched the diameter of the CAI which in turn resulted in better air flow. Now, the position of the MAF on the CAI was crucial because if placed too close to the curve in the tubing it resulted in irratic readings, which is why we placed the MAF as close to the TB as possible. (which is what Oldcat referred to when he said, "It seems to help if the MAF is put on right after the TB and has straight, smooth pipe after it. ")

The end result was not a huge HP gain, but it threw the max torque to HP ratio back down the curve instead of higher up closer to the top which resulted in getting my low end torque back, which is lost when you add a CAI and exhaust to the 3400, plus the flat spots and detonation were gone.

The stock MAF is calibrated for the stock air box, plain and simple.

Now....I'm also an old school guy and I'm not opposed to learning new things, but I do know what I know, and the end result was a car that ran consistant 15.7's ended up running consistant 15.4's and 5's on the same track. And when I say consistant I mean on a weekly basis, not on an occasional trip to the track.

Now someone can spout all of the numbers and technical jargon they know, but the bottom line is, the car was just faster, plain and simple, kids". :)

Now back to the original topic to remove or not to remove. Personally, I wouldn't do it because I'm not entirely sure that there's any noticable difference in just removing the screen.

I know Kelly has ported and polished his in addition to removing the screen and his car does run exceptionally well for the few mods that he's done and he doesn't have any problems with it. But don't forget, Kelly has been tearing down engines and working on cars long before the first Grand Am was introduced in 1973. I would be inclined to believe him if he says that he's noticed a difference.

[99GrandAMSE]

Originally posted by eric99gt
lol....way back when jason still ran gmpower. I've been around since the beginning of ga forums.

Cool ... just curious as I was aroung then too :)

[TA^Guy]

Originally posted by intake68
If you remove the sreens from either end it distorts the readings that the MAF is sending to the ECM.
Question then,

If the screen smooth out air flow for more accurate readings then why did GM remove them as one of their tricks when the Z06s hp rating went from 385hp to 405hp?

So GM is putting the motor at risk of inaccurate air flow messurments to help make a few more ponies?

Because on a motor like the LS6 that draws in much more air typically at a greater rate wouldn't the readings be even more off than our little 207cid motors?

BTW my screens have been out for 5 years now and never had any problems as a result of it.
Originally posted by intake68
Think of an engine like a pump. More air in and more air out is more power. False.
gasoline/fuel=power, not air.

Yes I know you need to maintain the proper air fuel ratio but without fuel your not going to go anywhere. The fuel is the stored energy, not the air.

[intake68]

Originally posted by TA^Guy
Question then,

If the screen smooth out air flow for more accurate readings then why did GM remove them as one of their tricks when the Z06s hp rating went from 385hp to 405hp?

The rear screen after the hotwire will act as a restriction when pulling air through the MAF on a 400HP car not on our econobox 170hp vehicles...



So GM is putting the motor at risk of inaccurate air flow messurments to help make a few more ponies?

Does GM produce these cars off the carlot brand new with screens removed???? Remove the screens, tell a GM tech, blow your engine and see if a conflict comes up with modifications and warranty issues.



Because on a motor like the LS6 that draws in much more air typically at a greater rate wouldn't the readings be even more off than our little 207cid motors?

What was the AFR at WOT on the first pull with the car with screens intact??? What was the AFR on the second pull with screens removed??? Did you not read in my posts the fact that I mentioned GM chose to be on the rich side when calibrating the ECM in regards to fueling???? What caused this??? Did the car lean out on the second pull or was the MAF itself the restriction???



BTW my screens have been out for 5 years now and never had any problems as a result of it.

Depending on what you have modified on the MAF you might have suffered some loss, its just more than likely that you are not informed enough or have the correct level of knowledge to really understand most of this I guess.




False.
gasoline/fuel=power, not air.

I was not making reference in how an internal combustion engine works, check the context. I was talking about restrictions and that by removing restrictions you allow more air to flow through the system. Its kinda a no brainer that extra fuel must be introduced dumb ass.....I have had enough, go and remove MAF screens all you want, but this whole topic has proven that most that have replied to this thread are guys that change their own oil and think they are somehow engineers. Don't take any of this from me, but do some actual research on this topic before adding opinions. As for the guy that went from a 15.7 to a 15.4 thats 30HP. I doubt you now have an engine that has 200HP with the screens removed....

[Fastlanev6]

As for the guy that went from a 15.7 to a 15.4 thats 30HP.

Or 300lbs, I believe :D

[Old Guy]

Originally posted by intake68
As for the guy that went from a 15.7 to a 15.4 thats 30HP. I doubt you now have an engine that has 200HP with the screens removed....

I'm the guy, and what I posted had nothing to do with taking screens out to increase HP. If you had read the entire post you would have seen that I said this:

Originally posted by Old Guy

Now back to the original topic to remove or not to remove. Personally, I wouldn't do it because I'm not entirely sure that there's any noticable difference in just removing the screen.



You have no idea what was done to the engine beyond the new MAF so don't question what the HP was. Besides, better track times do not always equate HP gains.

[Old Guy]

Originally posted by Fastlanev6
Or 300lbs, I believe :D

Yeah....I went on a crash diet!! :lol:

[Fastlanev6]

Originally posted by Old Guy
Yeah....I went on a crash diet!! :lol:

I KNEW it!!!!!!!!

[TA^Guy]

Originally posted by intake68
Does GM produce these cars off the carlot brand new with screens removed???? Remove the screens, tell a GM tech, blow your engine and see if a conflict comes up with modifications and warranty issues.
Here is my proof that you do not read, you just get defensive and start to babble.

There are no screen to remove, the 405hp ZO6 MAF has no screens in it, GM removed them, not I.

But your so intelligent you knew that right? You mention doing research, well brother you might want to take your own advice.

I'm sure you also know that many GN owners convert from the old style MASS to a MAF do not use the screens either. But what do guys that drive 11 second daily drivers know about that right?

Oh BTW smartguy, just because you disagree with someone, or just because we are on a 'Grand Am' site don't assume everyone here is new to this.

I'm sure you could learn alot from alot of the people here if you shut your yapper and opened your mind.

BTW, I do not need to defend my automotive knowledge to some clown online. I know what motors I've built, what turbos I've tuned and what nitrous systems I've installed. I also know what cars I have owned, where I have worked, and if I can handle a 9 second car or not.

And if you belittling people that disagree with give you a hard on then good for you, because I'm having fun watching you get all worked up in your "know it all" state of mind.

I mean I must be a total 'dumb ass' right? God, Jeez, your so absolutely right, what a idiot! Man your so smart. I mean you know everything right? Your like the godfather of knowledge! Shoot instead of doing research on why my velosity stacks are uneven I could have just asked you! Hey maybe I could show you a copy of a dyno sheet and you can tell me how to get rid of my 7000rpm dip!

:finger2:

Good Day.

[Colin]

:roflmfao:

[Fastlanev6]

wow

[99GrandAMSE]

... strange thread :lol:

[Desert Dog]

Removing the MAF screen.
Does this little mod bring any performance gains at all? I do know that in the 3100 the HP rating went down by 5 when they added the MAF sensor to it. Input? Thanks!
I think I have seen this argument on just about every car forum I have ever been on.

Specific intake designs work better with no screens on the MAF.

The screens are mainly there to keep your grubby hands off of the sensor filament. You touch the filament, you need a new sensor. And those little jewels, no matter what brand of car, are expensive.

The screen offers no decernible flow restriction and helps make the air more laminar for a more accurate airflow reading against the hot wire.

The new old guy will shut up now. :D

Mike

[99GrandAMSE]

Originally posted by Desert Dog
... The new old guy will shut up now. :D ...

No need to Mike ... I appreciate ALL opinions and comments provided they are put forth in a diplomatic and polite fashion :) ... thanks for the thoughts and welcome to the Club!! :)